Fix editor crash on startup

This temporarily disables the resource format loader in editor, which makes .ftl files
not show up in the file system.

Author: RedMser

rust/src/fluent/global.rs

@@ -1,23 +1,29 @@
 use godot::prelude::*;
-use godot::classes::ResourceLoader;
+use godot::classes::{Engine, ResourceLoader};
 
 use super::ResourceFormatLoaderFluent;
 
 /// Singleton for handling Fluent Translation. For internal use only.
 #[derive(GodotClass)]
 #[class(base=Object, init)]
 pub struct FluentI18nSingleton {
-    loader: Gd<ResourceFormatLoaderFluent>,
+    loader: Option<Gd<ResourceFormatLoaderFluent>>,
 }
 
 impl FluentI18nSingleton {
     pub(crate) const SINGLETON_NAME: &'static str = "FluentI18nSingleton";
 
-    pub(crate) fn register(&self) {
-        ResourceLoader::singleton().add_resource_format_loader(&self.loader);
+    pub(crate) fn register(&mut self) {
+        // HACK: Resource format loader crashes editor on startup, see https://github.com/godot-rust/gdext/issues/597
+        if !Engine::singleton().is_editor_hint() {
+            self.loader = Some(ResourceFormatLoaderFluent::new_gd());
+            ResourceLoader::singleton().add_resource_format_loader(&self.loader.clone().unwrap());
+        }
     }
 
     pub(crate) fn unregister(&self) {
-        ResourceLoader::singleton().remove_resource_format_loader(&self.loader);
+        if let Some(loader) = &self.loader {
+            ResourceLoader::singleton().remove_resource_format_loader(loader);
+        }
     }
 }

rust/src/lib.rs

@@ -25,8 +25,8 @@ unsafe impl ExtensionLibrary for FluentI18n {
         if level == InitLevel::Scene {
             project_settings::register();
 
-            let singleton = FluentI18nSingleton::new_alloc();
-            singleton.bind().register();
+            let mut singleton = FluentI18nSingleton::new_alloc();
+            singleton.bind_mut().register();
 
             Engine::singleton()
                 .register_singleton(FluentI18nSingleton::SINGLETON_NAME, &singleton);